#1 High voltage power lines :Definition
High voltage power lines or high-pressure lines are cables or electrical cables coming out of an electrical power station to connect the current for use in factories and homes. The cable carries a very high voltage of 100,000 volts or more and the electrical current in which it usually flows is AC(Alternativ current ).
The air acts as an insulator between the cables that carry the current. Wood towers, reinforced concrete, or interlocking iron bars can be used to build the towers for a voltage of less than 50 kV. As for the voltage above 50 kV, cross-linked iron towers are used in Europe. For voltages above 110 kV, interlocking iron pipes are also used to build the towers.
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For the purpose of protection from electric lightning strikes, the cable’s height from the ground should be at least 4 meters for the voltage less than 1000 V, and for the efforts above 1000 V (1 kilovolt), the cable’s height must be increased from that from the ground.
This high voltage is not directly suitable for normal use, but it reduces this high voltage in stages on the way to about 10,000 volts, then to about 3000 volts, and is used in factories when it has reached 760 volts. As for the use in homes and lighting in reducing the voltage to 220 volts in most countries, Some countries also use a 110-volt voltage for home use.
#2 Why are there red and white balls on power lines?
Colorful balls (Marker balls) are installed on the high-voltage landline to warn aircraft while flying.
The balls are made of plastic or aluminum, and they are orange, red, and white in color and each ball has a diameter of 60 cm.
These balls are 17 pounds (7.7 kg) and are attached to the highest line in the tower.
The distances between the balls should not be less than 40 meters according to the International Civil Aviation Organization. These balls cannot be seen at night unless they are highlighted.
These balls are installed near the airports, and there are rules and principles that govern the necessity of installing them according to the height of the aforementioned ground line and the distance from the airport runway, and whether the towers are located in the airliner’s take-off or landing corridor or otherwise.
As for the night aircraft warning, it is done by red light bulbs installed on the top of the towers or also in the middle of their height if they are high. These lamps derive energy from a low voltage source if available in the vicinity or from a solar cell system in areas far from urbanization.
#3 Different types of power lines (VHV, HV, MV, LV)
· The transport network: very high (VHV) and high voltage(HV) lines
- With minimal losses, VHT lines can transport large amounts of electricity over long distances. These lines, whose voltage exceeds 100 kilovolts (kV), constitute the principal network of transmission or interconnection. They allow regions and countries to be connected together as well as provide a direct supply of large urban areas. Most THT lines have a tension of 400 kV.
- The high-voltage lines constitute the regional distribution or supply network and allow transport on a regional or local scale. They transport electricity to heavy industries, large consumers of electricity such as rail transport and make the link with the second network. Their voltage is between 10kV and 100kV.
The distribution network: medium (MV) and low voltage(LV) lines
- Medium-voltage lines allow local power to be transported to small industries, SMEs, and businesses. They also make the link between the customers and the transformer stations of the current distribution companies. MV lines have a voltage between 15kV and 30kV.
- Low voltage lines are the smallest lines in the network. Their voltage is 230V or 400V. These are the ones that we use every day to power our household appliances. They, therefore, allow the distribution of electrical energy to households and artisans.
#4 What is the Blackout and how it happens ?
A threat to the electrical grid is the occurrence of so-called complete darkness (Blackout), and represents the state of the network’s failure to maintain a constant voltage and frequency resulting in all generation units being out of service and electricity being cut off from all loads.
As we know, the electrical grid is made up of connected generating plants to feed the electrical loads, but there’s no element of the grid that can store the power, and so the power generated is always temporarily exhausted.
Demand and generation must continue to be balanced. Millions of consumers with loads need effective capacity (P (MW), or other carriers need inefficient capacity (Q (MVA)), and generating stations must provide such orders in the meantime. So it’s a very complex system, and once that balance is broken, the whole system falls and it’s completely dark.
Suppose, for example, that at some time of the peak, when the grid is operating at the maximum generating capacity, a failure occurred at a generating station and it was abruptly discontinued and out of service. When this unit comes out, the other units must quickly provide the power needed to make up for the shortfall caused by the exit of that plant, but at peak time, as we said, all units operate at maximum capacity and cannot afford any increase in loads, and when an increase in generator loading begins. (overload) Systems of protection of these units take them off the grid so that the generator does not burn, and the situation becomes more complex, and exits may continue until we reach the Blackout, one scenario of Blackout occurrence.
#5 Electrocution problems
A major risk of electrical lines on birds
Above-ground electrical infrastructure represents a major risk to birds if some precautions are not taken, due to their size. And its large presence.
Most of the above-ground power lines (both medium and high voltage distribution lines) pose deadly risks to birds through collision with overhead cables and the risk of electric shock.
Bird collision occurs when a bird flies and collides physically with the power cable and usually, The bird is killed because of this collision, or because it occurred on the ground, or dies from injuries resulting from all of this.
As for electrocution, it happens When a bird bridges the gap between two charged elements or a charged element and a ground element. This results in a short circuit so that it flows The electric current through the
body of the bird is electrocuted and is often accompanied by a blackout.
In these countries, the problem of electrocution is a serious threat to a number of species, Especially storks and birds of prey that build their nests on electric towers or use poles as a place to rest.
Power lines are one of the main causes of abnormal bird deaths in a large portion of African-European and Asian flight paths. Collisions with species threatened with extinction from the first supplement to the bird protection directives in many European countries, for example, Spoonbill -Platalea leucorodia, and the problem also exist in Africa.
In South Africa, for example, many species of birds are threatened with extinction, such as the Blue Crane and Ludwig s Neotis, which are severely threatened because of the collision with the power lines.
The problem of electrocution is not just that an issue about bird conservation, but rather serious economic and financial consequences due to downtime and energy savings, which is a cause of concern among companies’ electricity distribution.
It is estimated that there are many millions of crash victims annually and there is a high proportion of victims. Black-tailed Godwit – Limosa Limosa in the Netherlands and Houbara and Eagle in Spain and Portugal.
Although at present electrocution is not a problem in northwest Europe, where most of the low voltage lines have been laid underground, however, there are still many countries, in Europe and elsewhere along the African-Eurasian flight paths, that no Sound in mitigating low and medium voltage lines.
#6 What is the solution to the problem of birds’ electrocution?
Underground power lines
There are many solutions to electrocution problems If power lines are to be constructed, constructing them under the ground provides the best solution to electrocution and bird collision problems.
In spite This is rarely implemented for a large area, due to technical and financial challenges, but it reduces harm to birds and contributes to the lives of millions of birds around the world.
Keep birds away from power lines
Optical deterrents have been tried in the past, “such as using silhouettes on columns to limit birds’ journeys over the lines, but they have proven ineffective. The problem with these devices is that birds get used to them, but as for audio or sound buddies, they enjoy blankets despite the absence of any articles proving their activities. With these deterrents, birds are not likely to get used to it, but the problem is that this cannot be applied over long distances in addition to its high costs and over time it will lose its impact.
This can be done in various ways, including surrounding the electricity line with trees, in order to attract birds to them instead of going to the electrical lines in order to manipulate the movement of birds, but this also requires significant financial and environmental costs.
Line design – less obstacle for birds
Although different types of birds fly at different altitudes above the surface of the earth, there is consensus that the lower the power cable line, the better it will be to prevent the collision of birds. There is also a consensus that vertical spacers pose less for birds.
Determining the power lines make it more visible to birds
Electric line marking devices
Since the assumption is that birds collide with hanging cables because they cannot see them, mounting them with devices in order to make them more visible to birds in the air has become the preferred option for mitigating collisions around the world. In addition to making the wire thicker or coating and coloring the wires less visible, there is a wide range of marking devices for power lines that have evolved over the years, including balls, swing boards, spiral dampers, tapes, flight guides, fins, and balls Aerials, tapes, flags, fishing rods, fly balls, and crosshairs.